Fuel problem ? Landmaster 88 with Aspera motor.

[sidevalve44]

I had the chance to try the Landmaster out today.

It took a while to warm up properly, but once warm, started digging well (almost too well, I had a job holding it back !). Then it started to cough and splutter and then cut out. It took several goes to get it going again and it proceeded to do this several times. Run OK for a couple of minutes, then falter, pick up again then falter before cutting out.

I am inclined to think this is a fuel supply problem as it is similar to something I have encountered on a lawnmower. What are your thoughts ?

Another thing: I have noticed the cylinder head bolts keep loosening. Every time I have run it, I have had to nip them back up again. This may be due to the copper-slip I put on them when re-assembling. I am inclined to get some spring washers and then remove the bolts, clean the threads and then re-assemble with threadlock on them instead. Will I need a new head gasket; what do you think ? I have never encountered this before, and I have done a few engines (all B&S) over the years.

[wristpin]

As a rule you should not lubricate head bolts – certainly not with Copperslip or similar. Many engine manufacturers will specify dry threads or, as in the case of BS, lightly oiled which is defined as a squirt of oil, wiped round with a paper towel to spread it and then remove all all surplus.
Not only does lubrication of head bolts encourage slackening but also makes a nonsense of initial torque settings. Also, the use of Loctite or similar thread locking compounds can have a similar effect resulting in the torque wrench not cracking off until after the stretch point of the bolt.
There are all sorts of differing opinions on this and a bit of Googling will bring up some interesting reading.

Back to your initial query, don’t rule out an ignition issue ranging from just dirty or maladjusted points to a failing condenser or coil. Don’t forget VICTOR – Valves, Ignition, Carburettor – in that order.

[sidevalve44]

Thanks for the advice, I will remove the head bolts and clean accordingly.

The coil, points and condensor are all brand new and the valves were ground in and gapped at .010″ex and .008″in (no data for Aspera so, I used B&S figures) so, these shouldn’t be a problem.

By the way, what should the torque figures be for the cyl head bolts ? My B&S repair book states 140lb/in. So I am guessing it should be the same for a Tecumseh.

[andyfrost]

Sort you cyl. head bolt issues , try again and get back to us.

Andy

[charlie]

Another consideration, if fuel is not fresh or has been left in the machine, is water in the fuel. The ethanol content of fuel can cause this. I had this on my Trusty Earthquake, draining out the float bowl I could see beads of water in the petrol.

[sidevalve44]

Hi Charlie,

The fuel was fresh, I put it in only a few minutes earlier.

[wristpin]

By the way, what should the torque figures be for the cyl head bolts ? My B&S repair book states 140lb/in. So I am guessing it should be the same for a Tecumseh.

The Tecumseh book says 12-16 ftlbs so with unlubricated threads you can afford to increase a bit from your BS setting.
Valve clearances. My Tec book says 6 thou inlet and 8 for the exhaust on the older engines. Small side valve Tecumseh have always been sensitive to the exhaust clearance . Set it on the wrong place on the cam and you will end up with a huge gap and wrist spraining kick back .
BS small side valves have always been 5-7 inlet and 7-11 exhaust for early ones and 7-9for later ones.

[Author]

Posts